episodes

Several portions of the long-running British science-fiction television programme Doctor Who are no longer held by the BBC. Between 1967 and 1978, the BBC routinely deleted archive programmes for various practical reasons—lack of space, scarcity of materials, and a lack of rebroadcast rights. As a result, 97 of 253 episodes from the programme's first six years are currently missing, primarily from seasons 3, 4 and 5, leaving 26 serials incomplete. Many more were considered lost until recovered from various sources, mostly overseas broadcasters.
Doctor Who is not unique in its losses, as many broadcasters routinely cleared their archives in this manner. Until the BBC changed its archiving policy in 1978, thousands of hours of programming in all genres were deleted. Other affected BBC series include Hancock's Half Hour, Dad's Army, Z-Cars, The Likely Lads, The Wednesday Play, Till Death Us Do Part, Steptoe and Son and Not Only... But Also. ITV regional franchisees, such as Rediffusion Television and Associated Television, also deleted many programmes, including early videotaped episodes of The Avengers.Doctor Who is unusual in that each of its 97 missing episodes survives in audio form, recorded off-air by fans at home. Most episodes are also represented by production stills, tele-snaps, or short video clips. Furthermore, after careful restoration, all 1970s episodes are available in full colour, apart from the first episode of Invasion of the Dinosaurs, which is not always the case for other series.
Efforts to locate the missing episodes have continued, both by the BBC and by fans of the series. The recovered episodes have been extensively restored for release on VHS and DVD; surviving soundtracks have been released on cassette and compact disc. Many missing episodes have had their visuals reconstructed, either through specially commissioned animation or use of surviving footage and photographs.

View More On Wikipedia.org